A method of manufacture of a float glass plate includes a step of forming molten glass, which is continuously supplied onto molten metal in a bath, into a band plate shape by allowing it to flow on the molten metal (for example, refer to Patent Document 1). The molten glass is cooled while flowing on the molten metal in a predetermined direction and pulled up from the molten metal in the vicinity of an outlet of the bath. The pulled glass is annealed in an annealing furnace and then is cut into a predetermined size and shape to obtain a float glass plate as a product.